A human (black), an African Elephant (gray), a Mastodon (french blue) and a Paraceratherium (sky blue)

The largest land animal alive today is the mighty African elephant, however even the largest adult bull elephants were dwarfed by the largest land mammal ever to exist.  The giant herbivore Paraceratherium stood 5.5 metres (18 ft) tall at the shoulder.  When standing upright the creature’s head (which was approximately the same size as character actor Danny Devito) was about 8 metres (26 ft) above the ground.  Although debate continues about how much the beast weighed, reasonable estimates suggest it could have massed from 15 to 20 metric tons which means that the animals were as large as mid-sized sauropod dinosaurs from the previous era.  Partial skeletons of Paraceratherium were discovered by different scientists at different times–which has confusingly resulted in three different names for the genus: 1) Paraceratherium  which means”near horn animal” in Greek; 2) Indricotherium which was derived from a mythical Russian progenitor-monster called the Indrik-Beast; and 3) Baluchitherium which means “Baluchistan beast”, in honor of Baluchistan, an arid portion of the Iranian plateau, where a fossil specimen was unearthed.  Paleontologists prefer to call the genus “Paraceratherium,” however, thanks to TV specials and museum shows the name “Indricotherium” remains popular with the public.

Artist’s Conception of Paraceratheriums Migrating (from asecic.org)

Paraceratheriums were perissodactyls.  The giant creatures were most closely related to the living rhinoceroses (although they shared ancestors with tapirs and horses as well).  Paraceratherium’s immense size allowed it to eat the branches and leaves of large trees.  They ranged across what is now Central Asia across Iran, India, Pakistan, Mongolia, Kazakhstan, and China.  The various species of Paraceratherium had long graceful necks somewhat like that of Okapis.  Additionally they possessed nimble elongated upper lips with which to strip leaves off of branches.  These lips were no quite trunks but probably resembled the long grasping snout/lips of tapirs.  Although Paraceratherium was closely related to rhinoceroses, they lacked the rhino’s characteristic horns—their giant size meant they did not need them.  The genus originated in the Eocene and flourished during the Oligocene—a golden age of perissodatyls.  However as the global cooling became more pronounced in the late Oligocene, the great creatures gradually vanished.

Fossil Paraceratherium skeleton in a museum